Core C. Cell Culture and Animal Models Core Core C, the Cell Culture and Animal Models Core, is an integrated, dedicated, essential component of the Program, which will provide materials and services to all four Projects of the Program. This Core supports the Projects by providing specialized cell culture facilities, resources and expertise, by maintaining active and frozen stocks of cell lines used by the Projects, by providing training in cell culture techniques when needed by researchersin the Projects, and by assisting with cell culture experiments or performing cell culture experiments when desired by the Program Leaders. In addition, the Core will oversee an SPF animal facility in which studies with mice can be performed. This colony is suitable for long term studies of genetically altered mice, immune deficient (nude) mice and mice immunosuppressed by irradiation and/or drug treatments. The equipment, supplies, and expertise needed to monitor animals for tumor development and to implant, measure,and treat tumors will be available in this Core facility. When desired by the Project Leaders, the Core will maintain mouse strains and animal tumor model systems, will train Project staff in the techniques used with these model systems, and will participate in the design, performance, and analysisof experiments using these mouse model systems.